In a warning posting on the PSNI Bangor Facebook page they said that by calling the psychoactive substance a "legal high" it gives the impression they are safe but go on to say this is "far from the case".

Last year the family of a Northern Ireland teeanger found dead on a housing estate called for a ban on legal highs.

The parents of 17-year-old Adam Owens from Newtownards Co Down blamed legal highs for his death.

The PSNI said: "The proper name is New Psychoactive Substances (NPS) and while they are presented as being legal, they may contain substances that are harmful to human health.

"There are very high risks involved in taking NPS because they are mind altering substances and you can never be sure of exactly what it contains, what side effects it could have or what long term damage it could cause.

"Police advice is simple – don’t take chances. In some places in Northern Ireland police have seized suspected NPS that have contained cannabis extract, making them illegal to possess or sell under the Misuse of Drugs Act."

The PSNI have issued a direct plea to parents to "intervene now" to ensure their children's safety.

It said: "If you are one of these parents, please act. Intervene now to ensure their safety. We would also appeal to teachers, youth leaders and even friends of anyone who thinks someone close is buying and taking these harmful substances. Please take the first step and bring it to someone’s attention.

"Local police continue to work with the community, Council and health authorities to ensure that anything which could compromise the safety of the public is taken off the streets.

"The PSNI want to hear from anyone who knows where people are buying New Psychoactive Substances from, and they can be contacted on the non-emergency number 101. Or ring the independent charity Crimestoppers on 0800 555 111 and tell them anonymously."